I've long wanted exhaust cutouts on the car for the track. The Borla ProXS mufflers I had installed originally are great in that they are very quiet at idle, cruse and even under light throttle. They really only open up at full tilt and even then they are not so loud. this is great for 99% of the driving I do with the car, I've always felt that "loud" is really only fun for a week or so. My first build I used Flowmasters and could not stand it after a few weeks. It did sound good when you wanted it to though.

And that brings us to the way the car is now. It's quiet, but I was getting tired of turbo Miatas out basing it at the track and at meets. I also hated how the audio on my in-car GoPro videos contained more sound from the suspension and the passenger seat belts clanging that the exhaust.  I actually purchased a set of cut outs from Summit only to find that there was no space anywhere to locate them on the exhaust system. I had to figure out a different way.

My first plan was to buy a set of 4 oxygen sensor bungs and caps and have them welded in in different spots on the system so I could "tune" the sound by taking out one or two at a time. I though about this and became afraid the sound would be too "poppy" due to the small diameter of the bungs. I wanted something a little larger in diameter. While searching I happened across a 1" NPT oil pan inspection bung and plug made by Moroso. I picked up a set and had Epic Tuning down the street from me weld them in.

Here's the result. The "ports" are pretty big in comparison to an oxygen sensor bung and they are located where I can pull them out while changing my rear wheels for a track day. We started the car up before sticking the plugs in and the sound was actually quieter than the Flowmasters I had back in the day. It was actually quiet enough I could actually keep them out on the street. We'll see how they make the car sound at the track on Monday.

6/9/2022 07:43:27 pm

Thanks for sharing your modification experience. Love it! I want to share a company who helps me with euro car maintenance. "Karl Knudsen Automotive". https://www.karlknudsen.com.au They have great mechanic with expertise with euro cars in particular. Once again, thanks!


Leave a Reply.